Qualifying athletes for exercise

An article from the e-journal of the ESC Council for Cardiology Practice

Vol.12,N°29 - 06 Aug 2014

Dr. Robert Skalik

All professional and amateur athletes with a recognised or suspected cardiovascular disease must undergo a specialised diagnostic and qualification process before a training program is prescribed or continued.

Topic(s):

Sudden Cardiac Death and Resuscitation

Background

Professional and amateur athletic training can cause pressure and volume overload of the cardiovascular system which in this situation may far exceed its ordinary exercise capacity. Extreme physical effort may be a trigger for serious and often fatal cardiovascular events in athletes with previously undetected underlying heart or vascular disease. Thus, every professional or amateur athlete with a recognised or suspected cardiovascular disease must undergo a specialised diagnostic and qualification process before a training program is prescribed or continued.Causes and consequences

Regular and very intensive athletic training is a tremendous burden for the cardiovascular system which often induces adaptational changes in its structure and function as observed in echocardiography and electrocardiography (ECG). However, these physiologic changes referred to as the “athlete’s heart” may coincide with structural cardiac disease and also be a cofactor for dramatic deterioration of clinical status in a certain group of athletes. According to Corrado et al. competitive sport activity enhances by 2.5 the risk of sudden death in adolescents and young athletes (1).The most important aftermath of cardiovascular diseases in athletes is exercise-induced ventricular arrhythmia - ventricular tachycardia (VT) and ventricular fibrillation (VF) (92-98%). It is well explained by the pathophysiology of arrhythmias. Ventricular arrhythmias depend on three interrelated factors:

Arrhythmogenic substrates which are congenital or acquired cardiovascular diseases

A trigger – in the case of endurance athletes, it is extreme physical exercise or sport event-related chest trauma

Pathophysiologic conditions such as autonomic nervous system dysregulation with excessive adrenergic stimulation, dehydration, heat stress and water-electrolyte imbalance which are often observed during strenuous physical effort.

According to the various accessible medical records, hypertrophic cardiomyopathy (HCM), congenital heart defects, premature coronary artery disease are the most frequent causes of cardiovascular events in athletes (2,3). Hypetrophic cardiomyopathy has been reported to be one of the leading causes of sport-related heart arrest and death in athletes and non-athletes (2). However, other cardiovascular abnormalities such as anomalies of coronary vessels, arrhythmogenic dysplasia of right ventricle (ADRV), mitral valve prolapse, myocarditis, coronary vessel bridge, Marfan Syndrome, bicuspid aortic valve, pulmonary thrombo-embolism and channelopathies also significantly contribute to cardiovascular risk in athletes.

Role of the cardiologistThe clinical cardiologist and sports cardiologist have three major roles in the screening process of professional or amateur athletes and athletic training candidates with cardiovascular diseases:

Identification of the risk of cardiovascular events by means of clinical examination (symptoms, physical examination, family history of cardiovascular diseases, biochemical markers of cardiovascular disease risk, history of alcohol and drug abuse, nicotine addiction, medication, illegal doping) and various diagnostic modalities (electrocardiography, cardiopulmonary exercise testing, echocardiography or magnetic resonance imaging)

Prescription of an appropriate exercise program (static, dynamic with low, moderate or high intensity)

Regular medical check-up.

I - Identification of cardiovascular risk before exercise prescription in athletes

1 - Medical history

The majority of sport–related cardiovascular events are induced by genetically determined diseases with an autosomal dominant pattern of inheritance, hence the importance of family history in identifying affected athletes. The family history of cardiovascular diseases is considered positive in athletes when close relatives had experienced a premature heart attack or sudden death (below 55 years of age in males and 65 years in females), or suffered from cardiomyopathy, Marfan syndrome, long QT syndrome, Brugada syndrome, severe arrhythmias, coronary artery disease, or other disabling cardiovascular diseases. The positive familial history can be especially helpful in athletes without any clinical symptoms of disease and should encourage a doctor to perform further necessary examinations (resting ECG, echocardiography, ECG Holter monitoring or eventually genetic tests). A certain number of athletes with rare and genetically conditioned cardiomyopathies (e.g. arrhythmogenic dysplasia of right ventricle) may not have any preceding symptoms of disease (4). Personal history must be considered positive in the case of exertional chest pain or discomfort, syncope or near-syncope, irregular heartbeat or palpitations, and in the presence of shortness of breath, or fatigue unproportionate to the degree of physical effort (3). The seemingly noncardiac chest pain not related to physical exercise may also be caused by congenital or acquired cardiovascular disease (e.g. bicuspid aortic valve, dilatation or aneurysm of ascending aorta) and should be investigated before intensive training is started.

Resting ECG record can be especially valuable in diagnosis of potentially lethal pathologies in athletes such as long and short QT syndrome, Brugada syndrome, ARVD and WPW. Unfortunately, resting ECG and ECG stress tests or even echocardiography can be nonproductive in congenital anomaly of coronary vessels. If this disease is suspected in young athletes (exercise-induced syncope of unknown origin, ventricular arrhythmia) computed tomography of coronary vessels can be indicated. Furthermore, electrocardiography can be normal in approximately 5% of patients with hypertrophic cardiomyopathy. Rowin et al. have recently demonstrated that 10 % of examined young patients with hypertrophic cardiomyopathy presented normal or nonpathologic ECG (8). Moreover, trained athletes without evident cardiovascular disease may occasionally show ECG abnormalities similar to those found in patients with HCM (9). Hence, echocardiographic screening should be considered as a diagnostic option especially in athletes with familial history of HCM, ARVD or sudden cardiac death and obviously in athletes with abnormal resting ECG and upsetting symptoms before exercise is prescribed. Although normal ECG has very strong negative predictive power in pre-participation screening of young athletes for HCM, the disease may develop in midlife and beyond in some individuals and can be precipitated by intensive training. Besides, ECG pathologic changes may precede the LV hypertrophy and should raise the suspicion of the disease in athletes with a family history of HCM. Then, regular ECG and echocardiography screening should be recommended especially in high risk groups of HCM athletes during a course of regular intensive training and after termination of competitive exercise.

In all, the recommended steps for comprehensive evaluation of athletes with congenital or acquired cardiovascular disease before exercise are:

History and physical examination

Assessment of ventricular function, aorta and pulmonary artery pressure by echocardiography or other imaging techniques

Assessment of arrhythmias/ischaemia and other electrical abnormalities by ECG

Recommendation on intensity and type of exercise and risk assessment by CPET (10) (Table 1Table 1: Recommendation on intensity and type of exercise and risk assessment by CPET.

II - Athletes with cardiovascular diseases

1 - Congenital and acquired heart defects

In patients with congenital heart defects (CHD), dynamic exercise is more advisable than static exercise. However, competitive sports are contraindicated in patients with some defects, due to high risk of malicious arrhythmias, such as Eisenmenger Syndrome, coronary artery anomalies, Ebstein anomaly, transposition of great vessels corrected by Mustrad, Senning or Rastelli procedure. As for the other congenital or acquired defects (presented below), exercise prescription depends on the severity of the defect, and the hemodynamics and clinical symptoms of the disease.

Tricuspid regurgitation

Any degree with right atrial pressure above 20mmHg: no competitive sports.

2 - Cardiomyopathies

Hypertrophic cardiomyopathy (HCM)

Athletes with definite diagnosis of HCM should not participate in competitive sports at all. Athletes with ECG abnormalities (such as markedly increased QRS voltage, diffuse T-wave inversion, deep Q-waves in precordial leads) suggestive of HCM should undergo detailed clinical examination (personal history, echocardiography, 24 h Holter monitoring). When sudden cardiac death (SCD) or HCM in the family are excluded, and in the absence of symptoms, arrhythmias and significant LV hypertrophy, and with a normal LV diastolic ﬁlling/relaxation on echocardiography and blood pressure response to exercise, there is no reason for restricting athletes from competitive low dynamic and low static sports (e.g. bowling, cricket, riflery, golf). However, periodical clinical and diagnostic follow-up is recommended.

Arrhythmogenic Dysplasia of Right Ventricle (ADRV)

Athletes with a definite diagnosis of ADRV are absolutely restricted from participating in sport activities even if they have very good exercise tolerance because of a very high risk of malicious ventricular tachyarrhythmia. ADRV is one of the most frequent causes of SCD in young athletes.

3 - Ischaemic heart disease (IHD)

IHD accounts for most exercise-related SCD, especially in individuals above 35 years of age. Athletes with a deﬁnite diagnosis of IHD and a high probability of cardiac events (ejection fraction below 50%, exercise-induced ischaemia above 1 mm ST depression in two leads on exercise testing at lower steps, exercise-induced dyspnoea or syncope, frequent and complex tachyarrhythmias at rest and/or during stress testing, significant stenotic lesion above 70% or left main stenosis above 50% on coronary angiography) are not allowed to participate in competitive sports. On the other hand, athletes with a deﬁnite diagnosis of IHD and a low probability of cardiac events (no exercise-induced ischaemia and normal exercise capacity according to age and gender on exercise testing, no complex tachyarrhythmias at rest and/or during exercise, coronary stenotic lesions below 50%, ejection fraction above 50% on echocardiography) can enter low-moderate dynamic and low static sports (e.g. bowling, cricket, riflery, golf, fencing, table tennis, volleyball, baseball). Post-CABG/PCI athletes, who do not show evidence of myocardial ischaemia on stress testing, are allowed to resume physical activity under supervision of a sport physician after completion of an out-patient cardiac rehabilitation and risk stratification as specified earlier.

4 - Systemic hypertension

Athletes with systemic hypertension can participate in sport activities provided risk stratification and appropriate management of hypertension according to general rules are observed.

Athletes with well controlled blood pressure and no other cardiovascular risk factors can participate in all sports.

Nonsustained ventricular tachycardia: all sports are recommended in the absence of

Cardiac disease or arrhythmogenic condition

Symptoms and family history of SCD

Exercise-induced nsVT

Multiple episodes of nsVT with short RR interval

Athletes with symptomatic and asymptomatic pre-excitation should be advised to undergo electrophysiology study and preferably catheter ablation (if feasible) because of an increased risk of SCD before exercise prescription

Atrial flutter: ablation is mandatory before exercise prescription

Long QT and Brugada syndrome: no competitive sports

Conclusions

Cardiovascular diseases can carry an elevated risk of exercise-induced cardiac events and always require counseling by a cardiologist before the onset of athletic training. The type and intensity of exercise can be prescribed in athletes with cardiovascular problems after risk stratification based on detailed physical examination, family history, ECG, cardiopulmonary exercise testing and imaging techniques.

Notes to editor

Robert Skalik MD, PhDConsultant in cardiology, exercise physiologist Department of Physiology, Medical University of Wroclaw, PolandMember of the Working Group on Myocardial Function, ESCFormer consultant in echocardiography, Department of Cardiac Surgery, Medical University of Wroclaw, PolandVisiting consultant in cardiology and echocardiography, Department of Internal Medicine with Cardiology Subdivision, Regional General Hospital, Krotoszyn, PolandAuthors' disclosures: None declared.See also previous e-journal article on whether and how to establish an exercise program in heart failure patients 2012 European Guidelines on Cardiovascular Disease Prevention in Clinical Practice.High intensity exercise training.Heart Failure 2013 Congress report and sessions on exercise training.

The content of this article reflects the personal opinion of the author/s and is not necessarily the official position of the European Society of Cardiology.